A former substitute teacher at Easton Area High School admitted Thursday she had sex with a 17-year-old student in Easton Cemetery.

Kelly Aldinger faces up to seven years in prison after pleading guilty Thursday to institutional sexual assault, a third-degree felony.

The 49-year-old Palmer Township woman was found by a city police officer at 1:06 p.m. May 6 having sex with the boy in the cemetery off North Seventh Street.

Aldinger served as council president as recently as last fall at St. Paul's III Lutheran Church.

She'll be sentenced Dec. 5 in front of Northampton County Senior Judge Leonard Zito.

She pleaded guilty to the one charge she faced. The plea does not include any sentencing bargain, according to Assistant District Attorney Anthony Casola.

Aldinger was employed by Source 4 Teachers and placed at Easton Area High School as a substitute teacher. She has since been suspended indefinitely by Source 4 Teachers.

The 17-year-old was at one point taught by Aldinger, police said. The sexual relationship between Aldinger and the student began in 2015, though they initially met when the teen was in middle school, according to court documents.

Defense attorney Phil Lauer said witnesses will likely testify on Aldinger's behalf at the sentencing hearing.

"I have nothing to add at this point," he told the judge Thursday.

"Kelly is a good person and a good educator," Lauer said at Aldinger's preliminary arraignment in June.

Aldinger, of the the 2000 block of Maywood Street, is free on 10 percent of $50,000 bail.

Rudy Miller may be reached at rmiller@lehighvalleylive.com. Follow him on Twitter @RudyMillerLV. Find Easton area news on Facebook.